A nightclub was classed as suitable if it satisfied the following
criteria:
(1) It was a licensed venue, which served alcohol and opened
to the public after 22:00.
(2) It had a dedicated dancefloor area.
(3) An admission fee was charged at the door.
(4) It had a SEO.
To establish bar staff occupational noise exposure, 2 logging
dosimeters and a sound level meter (SLM) were used. Apart
from Club D, where only one bar employee was available,
2 bar-staff in each nightclub wore a tamperproof Type 2
dosimeter (Brüel and Kjaer 4445E). Microphones were
attached to the employee’s shoulder, 10 cm from the ear.
Both dosimeters were field calibrated at 114 dBA using a
sound calibrator before and after the sampling period. At a
minimum continuous one-minute, LAeq,T’s were recorded
between the hours of 23:30 - 01:00.
A Type 1 integrated SLM (Brüel and Kjaer 2238) was placed
in a fixed position behind the bar closest to the dancefloor in
each nightclub. The SLM was calibrated at 94 dBA using a
sound calibrator before and after use. The SLM recorded the
noise level in the bar area to establish a noise level trend.
The SLM was switched on at 23:30, 00:15, and 01:00 for
8 minutes in order to calculate a representative LAeq.